1. Field of the Invention
The present invention relates to a reusable specimen cartridge for use in a bio-analysis system, and particularly a bio-analysis cartridge that includes a tracking mechanism and protection mechanism for its contents, and more particularly to a capillary electrophoresis cartridge having such tracking mechanism and content protection mechanism.
2. Description of Related Art
Bio-analysis, such as DNA analysis, is rapidly making the transition from a purely scientific quest for accuracy to a routine procedure with increased and proven dependability. Medical researchers, pharmacologists, and forensic investigators all use DNA analysis in the pursuit of their tasks. Yet due to the complexity of the equipment that detects and measures DNA samples and the difficulty in preparing the samples, the existing DNA analysis procedures are often time-consuming and expensive. It is therefore desirable to reduce the size, number of parts, and cost of equipment, to ease sample handling during the process, and in general, to have a simplified, low cost, high sensitivity detector.
One type of DNA analysis instrument separates DNA molecules by relying on electrophoresis. Electrophoresis techniques could be used to separate fragments of DNA for genotyping applications, including human identity testing, expression analysis, pathogen detection, mutation detection, and pharmacogenetics studies. The term electrophoresis refers to the movement of a charged molecule under the influence of an electric field. Electrophoresis can be used to separate molecules that have equivalent charge-to-mass ratios but different masses. DNA fragments are one example of such molecules.
There are a variety of commercially available instruments applying electrophoresis to analyze DNA samples. One such type is a capillary electrophoresis (CE) instrument. By applying electrophoresis in a fused silica capillary column carrying a separation support medium (e.g., a buffer solution, a gel matrix having a particular gel-chemistry), the sample size requirement is significantly smaller and the speed of separation and resolution can be increased multiple times compared to the slab gel-electrophoresis method. These DNA fragments in CE are often detected by directing light through the capillary wall, at the components separating from the sample that has been tagged with a fluorescence material, and detecting the fluorescence emissions induced by the incident light or by means of absorbance detection techniques. In fluorescence type detection the intensities of the emission are representative of the concentration, amount and/or size of the components of the sample. In the past, Laser-induced fluorescence (LIF) detection methods had been developed for CE instruments. Fluorescence detection is often the detection method of choice in the fields of genomics and proteomics because of its outstanding sensitivity compared to other detection methods.
The capillary column may be a part of a removable cartridge that can be separated from the system for storage, transport or reuse. Because different cartridge may be pre-assembled with different content, for example, a different gel-chemistry, the content of the cartridge should be identified. Visual indicators may be provided to identify the cartridge and its contents. For example, a label (e.g., with a bar-code) or separate information sheet may be applied to the cartridge. In addition, in view of the reusability of the cartridge and defined usage or shelf life of the contents of the cartridge, a separate log may be associated with the particular cartridge for keeping track of the usage of the cartridge. However, a label only contains information at the time the label was placed on the cartridge. A separate information sheet could easily be misplaced or mismatched to different cartridge of different gel-chemistry, for example. Any update in the information much be applied manually by a user, such as by writing on the cartridge or reapplying a label, or maintaining accurate records in the separate log. In the laboratory environment, where important bio-analysis is being conducted (such as clinical diagnostics type applications, where FDA mandates proper record keeping steps i.e. patient record/info tracking), the manual step of keep track of updating or logging of information would present a potential for errors and omissions. It is therefore desirable to have a reusable capillary cartridge for use with a CE instrument that includes a mechanism to automatically track information associated with a particular cartridge.
The cartridge is pre-assembled with capillaries filled with a separation support medium the property of which may potentially deteriorate with prolonged exposure to the environment. Given that the reusable cartridge may be stored in-between use, the separation support medium exposed at the tip of the capillaries would be most likely to deteriorate, such as drying of a gel matrix, causing blockage of the capillaries and creating issues when the cartridge is reused. It would be desirable to improve the life of the cartridge and its contents during storage.